Motor vehicles with transmissions that have form-locking shift elements and/or friction-locking shift elements are known from the practice. For friction-locking shift elements, there can be a relatively large rotational speed difference between an input-side component and an output-side component of a friction-locking shift element when the friction-locking shift element closes, wherein this rotational speed difference can be reduced by friction power at the friction-locking shift element. In contrast, the closing of a form-locking shift element requires that a defined, relatively low rotational speed difference be met between an input-side component and an output-side component of the form-locking shift element. This defined rotational speed difference typically varies between +400 rpm and −400 rpm. Within this rotational speed difference range, safe closing or engaging of a form-locking shift element can be ensured. In contrast, greater rotational speed differences can cause damage to the form-locking shift element. This must be avoided.
From DE 10 2009 028 305 A1, a method for operating a gearbox of a motor vehicle that comprises several friction-locking shift elements and at least one form-locking shift element is known, wherein according to this prior art, a rotational speed difference of the form-locking shift element is determined and a drive torque of the drive assembly is set to a level that keeps the rotational speed difference of the form-locking shift element within a predefined rotational speed range, within which the form-locking shift element has an approximately synchronous state and can be closed.